Hi Paul, the email form Jun 12 states that Protected Audience API implementation would be removed in M152. When I test on Chrome 152 stable, both navigator.joinAdInterestGroup and navigator.runAdAuction exist. Chrome Status entry <https://chromestatus.com/feature/6552486106234880> states that removal is planned for M153. Did the removal milestone get postponed by a milestone from 152 to 153?
Sincerely, Anton. On Saturday, July 18, 2026 at 11:38:05 PM UTC+3 Garrett Johnson wrote: > Paul, > Thanks for taking the time to respond and explain. This is a useful for me > to refer to when explaining this to the reader. > Warm regards, > > Garrett > > On Thursday, 16 July 2026 at 13:48:55 UTC-4 Paul Jensen wrote: > >> Garrett, >> >> >> When we marked the Protected Audience API as deprecated, in >> crrev.com/1545185, this included more of the API surface into the >> “Fledge” Blink use counter. You can see we added “DeprecateAs=Fledge” to a >> lot of the APIs in navigator_auction.idl in that change. It wasn’t >> actually an increase in API usage, it was just a change in measurement. >> You can see there were no corresponding spikes in particular API usage: >> https://chromestatus.com/metrics/feature/timeline/popularity/3855 >> https://chromestatus.com/metrics/feature/timeline/popularity/3857 >> >> On Tuesday, July 14, 2026 at 10:50:58 AM UTC-4 Garrett Johnson wrote: >> >>> I'm a researcher in this space who has ongoing research >>> <https://ssrn.com/abstract=4983927> measuring the adoption and use of >>> Privacy Sandbox tools. >>> >>> I'm hoping that someone in this chain could resolve a mystery for me >>> about the Fledge usage metrics in the Chrome Platform Status data here >>> <https://chromestatus.com/metrics/feature/timeline/popularity/4188>. >>> Basically, this approaches 0% of page loads in Q4 2025 as you would expect >>> given its retirement. However, usage spikes to its highest ever usage in Q1 >>> 2026 (peaking at 7.7%). This is unexpected: as mentioned above, auctions & >>> interest group activity has gone to almost 0 in the Chrome Platform Status >>> data (and my own). My guess is that some deprecation flag is being counted >>> here, but I really don't know. Other researchers >>> <https://arxiv.org/abs/2606.26390> found a similar spike in the HTTP >>> Archive data. >>> >>> I'd really appreciate your input here in setting the record straight on >>> whether PA API's post-retirement was in fact a mirage. Big bonus points if >>> you can explain why this happened. >>> >>> Sincerely, >>> >>> Garrett Johnson >>> Associate Professor >>> Questrom School of Business >>> Boston University >>> https://garjoh.com >>> >>> On Wednesday, 1 July 2026 at 14:25:39 UTC-4 Daniel Bratell wrote: >>> >>>> LGTM3 for steps 2 and 3. >>>> >>>> /Daniel >>>> On 2026-06-25 19:05, Chris Harrelson wrote: >>>> >>> LGTM2 >>>> >>>> On Thu, Jun 25, 2026 at 9:56 AM Yoav Weiss (@Shopify) < >>>> [email protected]> wrote: >>>> >>>> LGTM1 >>>>> >>>>> On Fri, Jun 12, 2026 at 2:32 AM Paul Jensen <[email protected]> >>>>> wrote: >>>>> >>>> Hi API Owners, Protected Audience API was deprecated in Chrome-144 >>>>>> with a plan to remove it in Chrome-150. Currently the usage is 1.1% >>>>>> of page loads. >>>>>> <https://chromestatus.com/metrics/feature/timeline/popularity/4188>We >>>>>> are proposing the following as next steps for removal and associated >>>>>> timelines: 1. M150: Remove all Ads API-related entries from Chrome >>>>>> settings and UI surfaces (e.g., chrome://settings/adPrivacy) via >>>>>> field trial. After this point, all API invocations for field-trial >>>>>> enabled >>>>>> browsers will always reject. Since the API can already be disabled for >>>>>> one >>>>>> of many reasons, scripts must already handle such rejections (or they’re >>>>>> already significantly broken). 2. M152: Permanently remove the >>>>>> underlying implementation code for the API, and replace it with a >>>>>> lightweight stub API. The stub will remain removable via field trial. >>>>>> >>>>>> 3. M152 Canary/Beta: Begin a controlled rollout of the stub API >>>>>> removal via a field trial. 4. M152 Stable: Assuming there are no >>>>>> regressions or breakage after reaching 1% stable, we will request >>>>>> additional approval for full removal at this stage. >>>>>> >>>>>> At this time, we are seeking LGTMs for steps #2 and #3. >>>>>> >>>>>> Thanks, >>>>>> >>>>>> Paul >>>>>> >>>>>> On Wed, Nov 12, 2025 at 11:30 AM Vladimir Levin <[email protected]> >>>>>> wrote: >>>>>> >>>>> LGTM2 >>>>>>> >>>>>>> On Wednesday, November 12, 2025 at 11:30:32 AM UTC-5 Chris Harrelson >>>>>>> wrote: >>>>>>> >>>>>> LGTM1 >>>>>>>> >>>>>>>> On Fri, Nov 7, 2025 at 11:04 AM Paul Jensen <[email protected]> >>>>>>>> wrote: >>>>>>>> >>>>>>> Intent to Deprecate and Remove: Protected Audience >>>>>>>>> Contact emails >>>>>>>>> >>>>>>>> [email protected] >>>>>>>>> >>>>>>>> >>>>>>>>> Explainer >>>>>>>>> >>>>>>>>> https://github.com/WICG/turtledove/blob/main/FLEDGE.md >>>>>>>>> >>>>>>>>> Specification >>>>>>>>> >>>>>>>>> https://wicg.github.io/turtledove/ >>>>>>>>> >>>>>>>>> Summary The Protected Audience API provides a method of >>>>>>>>> interest-group advertising without third-party cookies or user >>>>>>>>> tracking >>>>>>>>> across sites. >>>>>>>>> >>>>>>>>> Following Chrome's announcement >>>>>>>>> <https://privacysandbox.com/news/privacy-sandbox-next-steps/> >>>>>>>>> that the current approach to third-party cookies will be maintained, >>>>>>>>> we are >>>>>>>>> now planning to deprecate and remove >>>>>>>>> <https://privacysandbox.com/news/update-on-plans-for-privacy-sandbox-technologies/> >>>>>>>>> >>>>>>>>> the Protected Audience API (along with certain other Privacy Sandbox >>>>>>>>> APIs, >>>>>>>>> as outlined on the Privacy Sandbox feature status page >>>>>>>>> <https://privacysandbox.google.com/overview/status>). >>>>>>>>> >>>>>>>>> Blink component >>>>>>>>> >>>>>>>>> Blink>InterestGroups >>>>>>>>> <https://issues.chromium.org/issues?q=customfield1222907:%22Blink%3EInterestGroups%22> >>>>>>>>> >>>>>>>>> Web Feature ID >>>>>>>>> >>>>>>>>> None >>>>>>>>> >>>>>>>>> Motivation >>>>>>>>> >>>>>>>>> Chrome has announced that the current approach to third-party >>>>>>>>> cookies will be maintained. Since that announcement there has >>>>>>>>> been virtually no interest in the Protected Audience API. Use of >>>>>>>>> the joinAdInterestGroup() API >>>>>>>>> <https://chromestatus.com/metrics/feature/timeline/popularity/3855> >>>>>>>>> has decreased by almost 100x and use of the runAdAuction() API >>>>>>>>> <https://chromestatus.com/metrics/feature/timeline/popularity/3857> >>>>>>>>> has decreased by more than 10x. Of the auctions occurring today, >>>>>>>>> virtually >>>>>>>>> none of them have winners (determined by looking at the “Success” >>>>>>>>> bucket >>>>>>>>> count of the Ads.InterestGroup.Auction.Result UMA), implying that >>>>>>>>> they are >>>>>>>>> not providing useful benefit to the pages initiating them. >>>>>>>>> >>>>>>>>> Initial public proposal >>>>>>>>> >>>>>>>>> >>>>>>>>> https://privacysandbox.com/news/update-on-plans-for-privacy-sandbox-technologies/ >>>>>>>>> . >>>>>>>>> >>>>>>>>> Developer-facing impact >>>>>>>>> >>>>>>>>> Given that virtually none of the Protected Audience auctions >>>>>>>>> occurring today have winners, we estimate the lost utility from this >>>>>>>>> removal to be negligible. >>>>>>>>> >>>>>>>>> User-facing risks >>>>>>>>> >>>>>>>>> The user-facing risks are small. While removing the JavaScript API >>>>>>>>> could cause pages to break, the impact should be limited to sites >>>>>>>>> that >>>>>>>>> don't employ standard defensive coding or feature detection, which >>>>>>>>> should >>>>>>>>> be rare since not all browsers implement the API. >>>>>>>>> >>>>>>>>> If usage warrants, we will take steps to avoid any risk of page >>>>>>>>> breakage, e.g. by temporarily retaining a stub implementation of >>>>>>>>> Navigator >>>>>>>>> APIs joinAdInterestGroup(), runAdAuction(), leaveAdInterestGroup(), >>>>>>>>> clearOriginJoinedAdInterestGroups(), getInterestGroupAdAuctionData(), >>>>>>>>> >>>>>>>>> canLoadAdAuctionFencedFrame(), createAuctionNonce(), >>>>>>>>> updateAdInterestGroups(), protectedAudience.queryFeatureSupport(), >>>>>>>>> deprecatedReplaceInURN(), deprecatedURNtoURL(), and >>>>>>>>> adAuctionComponents() >>>>>>>>> that mimic current behavior when a user has disabled Protected >>>>>>>>> Audience. >>>>>>>>> >>>>>>>>> Estimated milestones >>>>>>>>> >>>>>>>>> Planning to deprecate in M144 and remove in M150. >>>>>>>>> >>>>>>>>> Currently 0.22% >>>>>>>>> <https://chromestatus.com/metrics/feature/timeline/popularity/4188> >>>>>>>>> of page loads use the Protected Audience API. These are driven by a >>>>>>>>> small >>>>>>>>> number of third-party ad tech scripts present on a large number of >>>>>>>>> sites. >>>>>>>>> We will continue to monitor usage as well as provide comprehensive >>>>>>>>> updates >>>>>>>>> on privacysandbox.google.com with the status of the API and >>>>>>>>> deprecation plans >>>>>>>>> <https://privacysandbox.google.com/overview/status>. >>>>>>>>> >>>>>>>>> We will also proactively work toward reducing usage to low levels >>>>>>>>> once this intent is approved, including disallowing any new >>>>>>>>> enrollment >>>>>>>>> sign-ups, and contacting enrolled sites to inform them about the >>>>>>>>> deprecation timelines. >>>>>>>>> >>>>>>>>> Protected Audience features that were never launched beyond 20% >>>>>>>>> Stable (TextEncoder support >>>>>>>>> <https://github.com/WICG/turtledove/issues/961#issuecomment-2793763963>, >>>>>>>>> >>>>>>>>> Creative scanning via BYOS/V1 trusted scoring signals >>>>>>>>> <https://groups.google.com/a/chromium.org/g/blink-dev/c/EXfp34Qb1oc/m/oaiY6MENBwAJ>, >>>>>>>>> >>>>>>>>> Selectable Reporting IDs >>>>>>>>> <https://groups.google.com/a/chromium.org/g/blink-dev/c/1cWqBPHngd0/m/gSYeR_dPAAAJ>) >>>>>>>>> >>>>>>>>> will be ramped down by the end of 2025. >>>>>>>>> >>>>>>>>> Protected Audience services, Bidding and Auction services >>>>>>>>> <https://groups.google.com/a/chromium.org/g/blink-dev/c/CyXJz3xOEcc/m/1snkv2KhAwAJ> >>>>>>>>> >>>>>>>>> and Trusted Key Value service >>>>>>>>> <https://groups.google.com/a/chromium.org/g/blink-dev/c/fH8u7ZTNZg8/m/oo0WVw7SAQAJ>, >>>>>>>>> >>>>>>>>> will not onboard new clients once deprecation is approved. We will >>>>>>>>> work >>>>>>>>> with onboarded clients and plan to turn down the services by the end >>>>>>>>> of >>>>>>>>> year as usage is negligible today. This will have no user-facing or >>>>>>>>> web-compat impact. >>>>>>>>> >>>>>>>>> Link to entry on the Chrome Platform Status >>>>>>>>> >>>>>>>>> https://chromestatus.com/feature/6552486106234880 >>>>>>>>> >>>>>>>> -- >>>>>>>>> You received this message because you are subscribed to the Google >>>>>>>>> Groups "blink-dev" group. >>>>>>>>> >>>>>>>> To unsubscribe from this group and stop receiving emails from it, >>>>>>>>> send an email to [email protected]. >>>>>>>> >>>>>>>> >>>>>>>>> To view this discussion visit >>>>>>>>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CABQTWrnevtY14OMos%2BuDgzXtFwQJ5vzY3hEMmyRFQBKDHBz-9A%40mail.gmail.com >>>>>>>>> >>>>>>>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CABQTWrnevtY14OMos%2BuDgzXtFwQJ5vzY3hEMmyRFQBKDHBz-9A%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>>>>>>> . >>>>>>>>> >>>>>>>> -- >>>>>> You received this message because you are subscribed to the Google >>>>>> Groups "blink-dev" group. >>>>>> >>>>> To unsubscribe from this group and stop receiving emails from it, send >>>>>> an email to [email protected]. >>>>> >>>>> >>>>>> To view this discussion visit >>>>>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CABQTWrmRRxZO%3D%2BCmt-hfkBBjeR8j4umTer8krMvmAyiVP_1HXw%40mail.gmail.com >>>>>> >>>>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CABQTWrmRRxZO%3D%2BCmt-hfkBBjeR8j4umTer8krMvmAyiVP_1HXw%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>>>> . >>>>>> >>>>> -- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "blink-dev" group. >>>>> >>>> To unsubscribe from this group and stop receiving emails from it, send >>>>> an email to [email protected]. >>>> >>>> >>>>> To view this discussion visit >>>>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAOmohS%2BRQAUtSUZw%3D4TsVgNOxcuR5aeQhym2CZO-_WmzUnndLQ%40mail.gmail.com >>>>> >>>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAOmohS%2BRQAUtSUZw%3D4TsVgNOxcuR5aeQhym2CZO-_WmzUnndLQ%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>>> . >>>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "blink-dev" group. >>>> >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to [email protected]. >>>> >>>> To view this discussion visit >>>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAOMQ%2Bw94fqnFNWSUWQSm7crPrzuLbO6Cz5p9Rg0BLEJsU%3DHPPg%40mail.gmail.com >>>> >>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAOMQ%2Bw94fqnFNWSUWQSm7crPrzuLbO6Cz5p9Rg0BLEJsU%3DHPPg%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>> . >>>> >>>> -- You received this message because you are subscribed to the Google Groups "blink-dev" group. 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